In typical commercial or industrial laundry processes, textile materials such as sheets, towels, wipes, garments, tablecloths, etc. are commonly laundered at elevated temperatures with alkaline detergent materials. Such detergent materials typically contain a source of alkalinity such as an alkali metal hydroxide, alkali metal silicate, alkali metal carbonate or other such base component. Additionally, such laundry chemicals typically contain anionic or other detergent materials that can enhance soil removal from the woven material. Such detergents also contain other components such as bleaches, brightening agents, antiredeposition agents, etc. that are used to enhance the appearance of the resulting cleaned article. Often the resulting cleaned items are then contacted with a commercial or industrial sour material. The residual components of the alkaline detergents remaining in or on the laundered item can result in fabric damage and skin irritation by the wearer of the washed fabric. This is particularly a problem with towels, sheets and garments. Sour materials contain acid components that neutralize alkaline residues on the fabric.
An important long felt need in laundry processing is the goal of obtaining cleaned and sanitized laundry items. A substantial reduction of bacteria, fungi, spores and other microorganisms or microorganism generating materials is important particularly in the medical, food processing and hospital industries. The substantial reduction in (more than five orders of magnitude, a five-log.sub.10 reduction) microorganisms is considered to be a sanitizing result. Laundry chemicals in laundry processes have long been sought that can provide sanitizing of laundered items without the use of strong, corrosive or otherwise dangerous or unpleasant chemicals. Presently, chemicals that have been used in the art include quaternary ammonium compounds, strong chlorine based sanitizers, and other strong chemicals. Such materials often result in forming laundered items that can provide skin irritation. The cleaning materials can be offensive or irritating in odor or inhalation toxicity, can have a deleterious effect on fabric or institutional laundry equipment, can be chemically unstable, expensive, etc.
Examples of laundry chemical detergent additives are shown in the art. Spadini et al., U.S. Pat. No. 4,220,562, disclose a peracid bleaching material adapted for stain removal containing an organic peroxy compound, an alkoxylated nonionic surfactant and other materials useful in stain removal. Spadini et al. suggest that a variety of conventional laundry components can be combined with the disclosed materials.
Hardy, U.S. Pat. No. 4,619,779, discloses a detergent additive product comprising a C.sub.5 -C.sub.18 aliphatic peroxycarboxylic acid bleach precursor. The bleach material typically includes the peracid bleach precursor combined with a flexible substrate. The bleach precursor can also be used with activators, detergents and other conventional laundry chemicals.
Trabitzsch, DE 3929335, discloses peroxy salts and peroxy generating compounds as well known detergent additive compositions that can be incorporated into laundry chemical compositions to use the peroxy function as a bleaching material. Trabitzsch suggests that these peracid materials are effective bleaches, but fail to emphasize that these materials can be used in a laundry step after the alkaline detergent in a stage that sanitizes, softens and neutralizes alkaline residues.
Kramer et al., U.S. Pat. No. 5,320,805, disclose methods of using laundry chemicals as a cleaner, sanitizer, disinfectant, sporicide, fungicide and sterilizer using an alkaline water soluble salt comprising hydrogen peroxide and phosphonium, sulfonium, quaternary ammonium or other such salts in a liquid soluble phase transfer material. The Kramer et al. technology involves interaction between a peroxy material such a perborate, persilicate, persulfate, peracetate or perphosphate and a quaternary ammonium material in a laundry detergent composition. The compositions of the invention are exemplified as containing a sodium carbonate peroxide material combined with a conventional quaternary ammonium compound and a EO-PO block copolymer.
Tieckelmann et al., U.S. Pat. No. 5,205,835 teaches a process for removing manganese dioxide residue from wet processed denim garments by neutralizing the alkaline fabric character with peracetic acid neutralizing agent. This patent is directed to permanganate bleached denim. The removal of the permanganate residue from the treated denim is a common problem in denim processing that is not typical in conventional, commercial or institutional laundry processes. Typically, laundry items contain no permanganate since they are used items and not permanganate processed prior to initiating laundry processing. Accordingly, the laundry items and the processes of the invention are typically permanganate free.
A long felt need in this industry has existed for effective laundry chemicals and processes that are highly effective in soil removal, fabric sanitization and sour soft properties. Such materials should remove oily and greasy soils, kill or substantially reduce the populations of bacteria, fungi, viruses and other harmful or illness causing pathogens. Lastly, the laundered material should be rendered soft and compatible with human contact. In use, the compositions of the present invention can be used in a single step following an alkaline laundry detergent step to improve the character and quality of the laundered product by providing both softness and sanitizing.